In the prior art, an artificial ground of Patent Publication 1 (JP-A-2002-4482) is disclosed as the technique relating to the structure for supporting the external force to be loaded on the planting portion. This artificial ground is constructed by laying a moisture-preventing sheet on the surface of a concrete layer, by arranging pallets on the surface of the sheet, by protruding a plurality of pins upward from the upper faces of the pallets, by arraying the plural pins at a spacing for receiving the lower faces of the shoes of a person walking on the pallets, and by laying soil on the pallets substantially up to the height of the pins.
Another relating technique is directed to a planting mat to be laid on the artificial ground, as disclosed in Patent Publication 2 (JP-A-11-289876). This planting mat is made by erecting post-shaped members of such a height in a cell recessed to have an upper portion opened and formed to have a water supply port near the bottom as not to exceed the upper end portions of the side walls of the cell.
In Patent Publication 3 (JP-A-10-98950), there is disclosed as another relating technique a lawn root protector, which is made by welding pipe posts in a staggered arrangement to an upper plate, by forming holes between the pipe posts, by attaching enclosing plates upward at a height substantially equal to that of the pipe posts, to the four sides of the upper plate, and by disposing a grid-shaped base plate at the lower portion of the upper plate so as to support the upper plate.
A pot is disclosed in Patent Publication 4 (JP-A-2001-57817) as a technique relating to the construction, in which a water-reserving unit for reserving water below a planting unit filled with soil or the like for cultivating plants. This pot is provided with: a water-reserving pot member capable of reserving water; a planting pot member laid on the water-reserving pot member for the plants; water supply means made of cloth for supplying water stored in the water-reserving pot member into the planting pot member; and a support member for supporting the bottom portion of the pot member on at least the pot member and the water-reserving pot member.
In another relating technique of Patent Publication 5 (JP-UM-A-61-20140), there is disclosed a pot receiving dish, in which a protrusion is formed of a number of needles in the recess of the dish body for supporting the bottom of the pot.
In another relating technique of Patent Publication 6 (JP-A-2001-78582), there is disclosed a plant cultivating container relating to the construction, in which a water-reserving unit is disposed below a planting unit for plants for supporting an external force to be loaded on the planting unit. The plant-cultivating container disclosed is constructed of a bottom plate and a circumferential wall, and has its upper face opened. In this plant-cultivating container, a unit placing space is formed in an upper portion of the container, and a breeding material filled space is formed in the lower portion. A plurality of post-shaped members for supporting the unit material placed in the unit placing space are erected from the bottom plate, and legs are formed downward from the bottom plate. The plant-cultivating container is laid on a water-reserving bath tray.